Image sensor including phase detection pixel

ABSTRACT

Provided is an image sensor including a pixel array which provides a plurality of pixels arranged in rows and columns. The plurality of pixels include: a plurality of image sensing pixels each including a plurality of image sensing sub pixels that include the same color filter; and a plurality of phase detection pixels each including at least one phase detection sub pixel which generates a phase signal for calculating a phase difference between images, wherein the plurality of image sensing sub pixels included in the same image sensing pixel are connected to one selection signal line and receive the same selection signal.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of priority under 35 U.S.C. § 119(e)to Korean Patent Application No. 10-2017-0069771, filed on Jun. 5, 2017,in the Korean Intellectual Property Office, the disclosure of which isincorporated herein in its entirety by reference.

BACKGROUND

The present disclosure relates to an image sensor, and moreparticularly, to an image sensor including a phase detection pixel.

Image sensors that capture images and convert them into electricalsignals are used in cameras installed in automobiles, security devices,and robots, as well as in general consumer electronic devices such asdigital cameras, mobile phone cameras, and portable camcorders. Each ofsuch image sensors has a pixel array, and each pixel included in thepixel array may include an optical sensing element. In general, an imagesensor may be required to perform an auto-focusing function so thatimage shooting can be performed quickly and accurately.

SUMMARY

The present disclosure provides an image sensor capable of ensuringimage quality while quickly performing an auto-focusing function.

According to an aspect of the inventive concept, there is provided animage sensor including a pixel array which provides a plurality ofpixels arranged in rows and columns, wherein the plurality of pixelsinclude: a plurality of image sensing pixels each including a pluralityof image sensing sub pixels that include the same color filter; and aplurality of phase detection pixels each including at least one phasedetection sub pixel configured to generate a phase signal forcalculating a phase difference between images, wherein the plurality ofimage sensing sub pixels included in the same image sensing pixel areconnected to one selection signal line and receive the same selectionsignal.

According to another aspect of the inventive concept, there is providedan image sensor including a pixel array which provides a plurality ofpixels arranged in rows and columns, wherein the plurality of pixelsincludes: a plurality of image sensing pixels each configured togenerate an image signal; and a first phase detection pixel and a secondphase detection pixel configured to generate different phase signals forcalculating phase differences between images, wherein a ratio of thenumber of the first phase detection pixels and the number of the secondphase detection pixels to the number of the plurality of pixels arrangedin the pixel array has a value of 1/16 or 1/32.

According to another aspect of the inventive concept, there is providedan image sensor including: a pixel array including a plurality of phasedetection pixels and a plurality of image sensing pixels; and a rowdriver configured to generate signals for controlling the pixel array,wherein each of the plurality of phase detection pixels includes atleast one phase detection sub pixel, and each of the plurality of imagesensing pixels includes a plurality of image sensing pixels connected tothe row driver through one selection signal line and receive the sameselection signal.

BRIEF DESCRIPTION OF THE DRAWINGS

Example embodiments of the inventive concept will be more clearlyunderstood from the following detailed description taken in conjunctionwith the accompanying drawings in which:

FIG. 1 is a view of an exemplary structure of a digital imaging deviceaccording to an example embodiment of the inventive concept;

FIG. 2 is a block diagram of a configuration of an image sensoraccording to an example embodiment of the inventive concept;

FIG. 3 is a view of an example embodiment of a pixel array of FIG. 2,and a pixel array of FIG. 3 shows a portion of a pixel array of FIG. 2;

FIGS. 4A and 4B are views for explaining an example embodiment of ashared phase detection pixel of FIG. 3;

FIG. 5 is a cross-sectional view of a first shared phase detection pixelof FIG. 4A, taken along a line A-A′;

FIGS. 6A to 6C are views for explaining arrangements of a plurality ofshared pixels included in the pixel array of FIG. 3;

FIG. 7 is a view for explaining a connection between a row driver ofFIG. 2 and a pixel array of FIG. 6A;

FIG. 8 is a view for explaining an example embodiment of a shared phasedetection pixel of FIG. 3;

FIG. 9 is a view for explaining arrangements of a plurality of sharedpixels included in the pixel array of FIG. 3;

FIG. 10 is a view for explaining an example embodiment of a shared phasedetection pixel of FIG. 3;

FIG. 11 is a view for explaining arrangements of a plurality of sharedpixels included in the pixel array of FIG. 3;

FIG. 12 is a view for explaining a connection between a row driver ofFIG. 2 and a pixel array of FIG. 10;

FIG. 13 is a view of an example embodiment of a pixel array of FIG. 2;

FIG. 14 is a view for explaining an example embodiment of shared phasedetection pixels of FIG. 13;

FIGS. 15A to 15C are views for explaining arrangements of a plurality ofpixels included in a pixel array of FIG. 2; and

FIGS. 16A and 16B are views for explaining arrangements of a pluralityof pixels included in a pixel array of FIG. 2.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Hereinafter, example embodiments of the inventive concept will bedescribed in detail with reference to the accompanying drawings.

FIG. 1 is a view of an exemplary structure of a digital imaging device1000 performing an Auto-Focus (AF) function, according to an exampleembodiment of the inventive concept.

According to an example embodiment of the inventive concept, the digitalimaging device 1000 may include a photographing unit 1100, an imagesensor 100, and a processor 1200 (e.g., a central processing unit(CPU)). The digital imaging device 1000 may have a focus detectionfunction.

All operations of the digital imaging device 1000 may be controlled bythe processor 1200. The processor 1200 may provide a control signal foroperation of each component to a lens driver 1120, an iris driver 1140,a controller 120, and the like.

The photographing unit 1100 may include a lens 1110, the lens driver1120, an iris 1130, and the iris driver 1140 as components for receivinglight. The lens 1110 may include a plurality of lenses.

The lens driver 1120 may adjust a position of the lens 1110 according tothe control signal provided by the processor 1200. The lens driver 1120may move the lens 1110 in a direction in which a distance of the lens1110 from an object 2000 increases or decreases. Thereby, the distancebetween the lens 1110 and the object 2000 may be adjusted. Depending onthe position of the lens 1110, the object 2000 may be focused ordefocused.

For example, if the distance between the lens 1110 and the object 2000is relatively short, the lens 1110 may be out of an in-focus position tofocus on the object 2000, and phase differences may be generated betweenimages captured by the image sensor 100. The lens driver 1120 may movethe lens 1110 in the direction in which the distance of the lens 1110from the object 2000 increases, based on the control signal provided bythe processor 1200.

Alternatively, if the distance between the lens 1110 and the object 2000is relatively long, the lens 1110 may be out of the in-focus position,and phase differences may be generated between images formed on theimage sensor 100. The lens driver 1120 may move the lens 1110 in thedirection in which the distance of the lens 1110 from the object 2000decreases, based on the control signal provided by the processor 1200.

The image sensor 100 may convert an incident light into an image signal.The image sensor 100 may include the pixel array 110, the controller120, and a signal processor 130. An optical signal transmitted throughthe lens 1110 and the iris 1130 reaches a light-receiving surface of thepixel array 110 and may form an image of a subject thereon.

The pixel array 110 may be a Complementary metal oxide semiconductorImage Sensor (CIS) that converts the optical signal into an electricalsignal. Sensitivity and the like of the pixel array 110 may be adjustedby the controller 120. The pixel array 110 may include a plurality ofpixels PX including a plurality of image sensing pixels IPX and aplurality of phase detection pixels PPX.

In some embodiments, the plurality of phase detection pixels PPX may bearranged in the pixel array 110 of a tetra-cell structure, e.g., astructure implemented using shared pixels including a plurality of subpixels to provide a wide dynamic range and a phase difference AFfunction. The term “shared pixels” as used in this disclosure may referto a plurality of pixel groups that are arranged to share certaincircuitry. For example, a pixel group may include a plurality of subpixels and at least some of the sub pixels in the pixel group may shareat least one of a reset transistor, a source follower transistor, andselecting transistor. In this implementation, each pixel group mayinclude four sub pixels and four photodiodes corresponding to each subpixel, but the disclosure is not limited thereto. The reset transistormay be activated to reset the floating charge accumulated by thephotodiodes connecting the photodiodes to a power supply Vdd removingall integrated charge from the previous exposure period. Source followertransistor may provide an analog pixel signal to column signal linecorresponding to the charge accumulated by a selected photodiode. Selecttransistor may operate to connect the analog pixel signal provided bythe source follower transistor to the corresponding column signal line.In this example, each pixel group may have transfer transistors, thereset transistor, the source follower transistor and the selectingtransistor that are not shared with other pixel groups. For example, aplurality of image sensing sub pixels included in the same shared imagesensing pixel IPX may be connected to one selection signal line and mayreceive the same selection signal. In some embodiments, the plurality ofphase detection pixels PPX may be arranged in the pixel array 110 at anappropriate ratio so that the image sensor 100 may provide an efficientcompensation function and a phase difference AF function whilemaintaining a high resolution. For example, a ratio of the number ofphase detection sub pixels arranged in the pixel array 110 to the numberof the plurality of shared pixels arranged in the pixel array may be1/32 in one embodiment or 1/64 in another embodiment. This will bedescribed in detail later below with reference to FIG. 2 and the like.

The processor 1200 may receive pixel information from the signalprocessor 130 to perform a phase difference calculation. A plurality ofphase detection pixels PPX included in the pixel array 110 may be usedto focus on an object. The plurality of phase detection pixels PPX maygenerate phase signals. The phase signals may include informationassociated with positions of images formed on the image sensor 100.Accordingly, the phase signals may be used to calculate phasedifferences between images. The in-focus position of the lens 1110 maybe calculated based on the calculated phase differences. For example, aposition of the lens 1110 where a phase difference is 0 may be thein-focus position. The processor 1200 may obtain a position of a focus,a direction of the focus, or a distance between the object 2000 and theimage sensor 100 as a result of the phase difference calculation. Theprocessor 1200 may output a control signal to the lens driver 1120 tomove the position of the lens 1110 based on the result of the phasedifference calculation.

The processor 1200 may reduce noise of an input signal and may performimage signal processing for improving image quality such as a gammacorrection, color filter array interpolation, a color matrix, a colorcorrection, color enhancement, and the like. In addition, the processor1200 may compress image data generated by the image signal processingfor improving image quality to generate an image file, or may restorethe image data from the image file.

FIG. 2 is a block diagram of a configuration of the image sensor 100according to an exemplary embodiment of the inventive concept.

As illustrated in FIG. 2, the image sensor 100 may include the pixelarray 110, the controller 120, the signal processor 130, a row driver140, and a signal reader 150.

The pixel array 110 may be formed in pixel units and may include aplurality of pixels PX. Each of the plurality of pixels PX may include acorresponding optical sensing element. For example, the optical sensingelement may be a photodiode. The plurality of pixels PX absorb light togenerate electric charges, and an electric signal (output voltage)according to the generated electric charge may be provided to the signalreader 150.

The pixel array 110 may include a plurality of image sensing pixels IPXand a plurality of phase detection pixels PPX. The plurality of imagesensing pixels IPX may generate image signals corresponding to anobject. The plurality of phase detection pixels PPX may generate phasesignals used for calculating phase differences between images. Aplurality of image sensing pixels and a plurality of phase detectionpixels may be arranged in pixel units PX.

The plurality of phase detection pixels PPX included in the image sensor100 may be used for focusing on an object. The phase signals generatedby the plurality of phase detection pixels PPX may include informationabout positions of the images formed on the image sensor 100. Thus, thephase signals may be used for calculating the phase differences betweenthe images. Based on the calculated phase differences, an in-focusposition of the lens 1110 (FIG. 1) may be calculated. For example, aposition of the lens 1110 (FIG. 1) that makes a phase difference zeromay be the in-focus position.

In an example embodiment of the inventive concept, the plurality ofphase detection pixels PPX may be used for measuring the distancebetween the object 2000 and the image sensor 100 as well as focusing onthe object 2000. Additional information such as phase differencesbetween images formed on the image sensor 100, a distance between thelens 1110 and the image sensor 100, a size of the lens 1110, an in-focusposition of the lens 1110, etc. may be referred to measure the distancebetween the object 2000 and the image sensor 100.

The controller 120 may control the row driver 140 so that the pixelarray 110 may accumulate electric charges by absorbing light, store theaccumulated electric charges temporarily, and output electric signalscorresponding to the stored electric charges to the outside of the pixelarray 110. In addition, the controller 120 may control the signal reader150 to measure an output voltage provided by the pixel array 110.

The row driver 140 may generate reset control signals RSs, transmissioncontrol signals TXs, and selection signals SELSs for controlling thepixel array 110 and provide the generated signals RSs, TXs, and SELSs tothe plurality of pixels PX included in the pixel array 110. The rowdriver 140 may determine activation and deactivation timings of resetcontrol signals RSs, transmission control signals TXs, and selectionsignals SELSs for the plurality of phase detection pixels PPX, based onwhether or not to perform an AF function.

The signal reader 150 may include a correlated double sampler (CDS) 151,an analog-to-digital converter (ADC) 153, and a buffer 155. The CDS 151may sample and hold the output voltage provided by the pixel array 110.The CDS 151 may double-sample a specific noise level and the providedoutput voltage, and may output a value corresponding to the differencebetween the specific noise level and the provided output voltage. Forexample, the CDS 151 may measure the output voltage provided by thepixel array 110 twice and subtract the first measured output voltagefrom the second measured output voltage to remove reset sampling noise.Generally, the sampling is performed once immediately following reset(e.g., the first measured output voltage) of a photodiode correspondingto a pixel of the plurality of pixels PX and once after the photodiodehas been allowed to accumulate a charge (e.g., the second measuredoutput voltage). The CDS 151 then subtracts the first measured outputvoltage from the second measured output voltage to remove reset samplingnoise. Furthermore, the CDS 151 may receive a ramp signal generated by aramp signal generator 157, compare the received ramp signals with eachother, and output the comparison result. The ADC 153 may convert ananalog signal corresponding to the level received from the CDS 151 intoa digital signal. The buffer 155 may latch the digital signal and thelatched signal may be sequentially output to the outside of the signalprocessor 130 or the image sensor 100.

The signal processor 130 may perform signal processing on data of theplurality of pixels PX to be received. The signal processor 130 mayperform noise reduction processing, gain adjustment, waveform shapingprocessing, interpolation processing, white-balance processing, gammaprocessing, edge enhancement processing, and the like. In addition, thesignal processor 130 may output information about the plurality ofpixels PX to the processor 1200 at the time of phase difference AF toperform a phase difference calculation.

In one example embodiment, the signal processor 130 may be provided inthe processor 1200 (FIG. 1) outside the image sensor 100.

FIG. 3 is a view of an example embodiment of the pixel array 110 of FIG.2. A pixel array 110 a of FIG. 3 shows a portion of the pixel array 110of FIG. 2.

Referring to FIGS. 2 and 3, the pixel array 110 a may include theplurality of pixels PX arranged according to a plurality of rows and aplurality of columns. For example, each shared pixel SPX defined as aunit including pixels arranged in two rows and two columns may includefour sub pixels. The sub pixels may be one of the plurality of pixelsPX. However, the present disclosure is not limited thereto, and each ofthe shared pixels SPX may include nine photodiodes respectivelycorresponding to nine pixels, or may include 16 photodiodes respectivelycorresponding to 16 pixels.

The pixel array 110 a may include the plurality of shared pixels SPXincluding a plurality of shared image sensing pixels SIPX0 to SIPX14 anda shared phase detection pixel SPPX. The plurality of shared imagesensing pixels SIPX0 to SIPX14 may include a plurality of image sensingsub pixels IPX and the shared phase detection pixel SPPX may include atleast one phase detection sub pixel PPX. The phase detection sub pixelPPX may be a pixel for phase difference detection AF, and the pluralityof image sensing sub pixels IPX may be general pixels capable ofobtaining only image information. A plurality of sub pixels included inone shared pixel SPX may be connected to one selection signal line andmay receive the same selection signal SELSs.

Each of the plurality of shared pixels SPX of the pixel array 110 a mayoutput a pixel signal to the CDS 151 through one of the first to(n−1)^(th) column output lines CLO_0 to CLO_n−1. For example, the firstshared image sensing pixel SIPX0 may be connected to the first columnoutput line CLO_0 to provide a pixel signal to the CDS 151, and theshared phase detection pixel SPPX may be connected to the second columnoutput line CLO_1 to provide a pixel signal to the CDS 151.

Each of the plurality of shared image sensing pixels SIPX0 to SIPX14 mayinclude a color filter to sense various colors. In an exampleembodiment, the color filter includes filters that sense red, green, andblue, and each of the shared image sensing pixels SIPX0 to SIPX14 mayinclude pixels in which the same color filter is disposed.

For example, each of the first shared image sensing pixel SIPX0, thesecond shared image sensing pixel SIPX1, the eighth shared image sensingpixel SIPX7, and the tenth shared image sensing pixel SIPX9 may includepixels having a red color filter, and each of the third shared imagesensing pixel SIPX2, the fourth shared image sensing pixel SIPX3, thesixth shared image sensing pixel SIPX5, the ninth shared image sensingpixel SIPX8, the 11th sensing shared pixel SIPX10, the 12th shared imagesensing pixel SIPX11, and the 14th shared image sensing pixel SIPX13 mayinclude pixels having a green color filter, and each of the fifth sharedimage sensing pixel SIPX4, the seventh shared image sensing pixel SIPX6,the 13th shared image sensing pixel SIPX12, and the 15th shared imagesensing pixel SIPX14 may include pixels having a blue color filter. Asillustrated in the exemplary embodiment of FIG. 3, one shared phasedetection pixel SPPX, configured to perform a phase difference AFfunction, is arranged at a position between the first shared imagesensing pixel SIPX0 and the second shared image sensing pixel SIPX1 in arow direction and above the fifth shared image sensing pixel SIPX4 in acolumn direction, but the disclosure is not limited thereto. The sharedphase detection pixel SPPX may be arranged at other positions of thepixel array 100 a for performing a phase difference AF function.

However, the present disclosure is not limited thereto. The plurality ofshared image sensing pixels SIPX0 to SIPX14 according to an exampleembodiment of the inventive concept may include various types of colorfilters. For example, the color filters may include filters for sensingyellow, cyan, magenta, and green colors. Alternatively, the colorfilters may include filters for sensing red, green, blue, and whitecolors. Also, the pixel array 110 a may include more shared pixels, andarrangements of the shared image sensing pixels SIPX0 to SIPX14 may bevariously implemented, and thus it is apparent that the presentdisclosure is not limited to FIG. 3.

The shared phase detection pixel SPPX may include a filter for sensinggreen color. However, the present disclosure is not limited thereto, andthe phase detection sub pixel PPX included in the shared phase detectionpixel SPPX may include filters for sensing white color.

Although only one shared phase detection pixel SPPX is shown in FIG. 3,the present disclosure is not limited thereto. Configuration andarrangement of the shared phase detection pixel SPPX will be describedin detail later below with reference to FIG. 4A and the like.

An image sensor including the pixel array 110 a according to the presentdisclosure may be controlled to detect light using a plurality ofoptical sensing elements included in the plurality of shared imagesensing pixels SIPX0 to SIPX14 in a low-resolution operation mode togenerate a pixel signal, so that a wide dynamic range may be securedeven under a low illuminance condition. Also, in a high-resolutionoperation mode, it is possible to individually control optical sensingelements corresponding to each sub pixel included in the plurality ofshared image sensing pixels SIPX0 to SIPX14 in order to generate pixelsignals in units of sub pixels included in the plurality of shared imagesensing pixels SIPX0 to SIPX14. Thereby, a wide dynamic range may beensured simultaneously without being restricted by structures of theshared pixels. In addition, the image sensor including the pixel array110 a according to the present disclosure further include the sharedphase detection pixel SPPX, so that the image sensor may perform a phasedifference AF function.

FIGS. 4A and 4B are views for explaining an example embodiment of theshared phase detection pixel SPPX of FIG. 3. FIG. 5 is a cross-sectionalview of the first shared phase detection pixel SPPX_a1 of FIG. 4A, takenalong a line A-A′.

Referring to FIGS. 3 and 4A, the shared phase detection pixel SPPX ofFIG. 3 may be a first shared phase detection pixel SPPX_a1 or a secondshared phase detection pixel SPPX_a2. The first shared phase detectionpixel SPPX_a1 and the second shared phase detection pixel SPPX_a2 mayinclude phase detection sub pixels PPX_a1 and PPX_a2 respectively, andmay further include a plurality of remaining image sensing sub pixelsIPX_G except for phase detection sub pixels.

According to an exemplary embodiment illustrated in FIG. 4A, the firstphase detection sub pixel PPX_a1 is disposed at a top left of the firstshared phase detection pixel SPPX_a1 and the second phase detection subpixel PPX_a2 is disposed at a top left of the second shared phasedetection pixel SPPX_a2. However, the present disclosure is not limitedthereto. The first phase detection sub pixel PPX_a1 and the second phasedetection sub pixel PPX_a2 may be disposed at the same position in thefirst shared phase detection pixel SPPX_a1 and the second shared phasedetection pixel SPPX_a2, respectively.

In an example embodiment, the plurality of image sensing sub pixelsIPX_G may include a green color filter, and each of the phase detectionsub pixels PPX_a1 and PPX_a2 may also include a green color filter. Inanother example embodiment, each of the phase detection sub pixelsPPX_a1 and PPX_a2 may include a white color filter.

The first phase detection sub pixel PPX_a1 may include a firstlight-shielding layer 111_1 and the second phase detection sub pixelPPX_a2 may include a second light-shielding layer 111_2. The firstlight-shielding layer 111_1 may be formed in a left-half portion of thefirst phase detection sub pixel PPX_a1 when the first phase detectionsub pixel PPX_a1 is divided to cross a column direction, and the secondlight-shielding layer 111_2 may be formed in a right-half portion of thesecond phase detection sub pixel PPX_a2 when the second phase detectionsub pixel PPX_a2 is divided to cross a column direction. Arrangements ofthe first shared phase detection pixel SPPX_a1 and the second sharedphase detection pixel SPPX_a2 of a pixel array according to the presentdisclosure will be described in detail later below with reference toFIGS. 6A and 6B.

Referring to FIGS. 3 and 4A, the shared phase detection pixels SPPX ofFIG. 3 may be the first shared phase detection pixel SPPX_a1 or thesecond shared phase detection pixel SPPX_a2. Third and fourth sharedphase detection pixels SPPX_a3 and SPPX_a4 may include phase detectionsub pixels PPX_a3 and PPX_a4, respectively, and may further include aplurality of remaining image sensing sub pixels IPX_G except for thephase detection sub pixels. The third and fourth phase detection subpixels PPX_a3 and PPX_a4 may be disposed at the same position in thethird and fourth shared phase detection pixels SPPX_a1 and SPPX_a2,respectively.

In an example embodiment, the plurality of image sensing sub pixelsIPX_G may include a green color filter, and each of the phase detectionsub pixels PPX_a3 and PPX_a4 may also include a green color filter.However, the present disclosure is not limited thereto. In anotherexample embodiment, each of the phase detection sub pixels PPX_a3 andPPX_a4 may include a white color filter.

The third phase detection sub pixel PPX_a3 of the third shared phasedetection pixel SPPX_a3 may include a third light-shielding layer 111_3and the fourth phase detection sub pixel PPX_a4 of the fourth sharedphase detection pixel SPPX_a4 may include a fourth light-shielding layer111_4. The third light-shielding layer 111_3 may be formed in an upperportion of the third phase detection sub pixel PPX_a3 when the thirdphase detection sub pixel PPX_a3 is divided to cross a row direction,and the fourth light-shielding layer 111_4 may be formed in a lowerportion of the fourth phase detection sub pixel PPX_a4 when the fourthphase detection sub pixel PPX_a4 is divided to cross a row direction.Arrangements of the third and fourth shared phase detection pixelsSPPX_a3 and SPPX_a4 of a pixel array according to the present disclosurewill be described in detail later below with reference to FIG. 6C.

Referring to FIGS. 4A and 5, the first phase detection sub pixel PPX_a1may include an optical sensing element PD_1, the first light-shieldinglayer 111_1, an insulating layer 113_1, a color filter layer 115_1, anda micro lens 117_1. The first light-shielding layer 111_1 may be formedon the insulating layer 113_1 and may include a metal material. Theplurality of image sensing sub pixels IPX_G includes an optical sensingelement PD_2, an insulating layer 113_2, a green color filter layer115_2, and a micro lens 117_2, but does not include a light-shieldinglayer.

Because of the first light-shielding layer 111_1, the optical sensingelement PD_1 may not receive a part of light incident on the firstshared phase detection pixel SPPX_a1. There may be a difference in theamount of light when a light 200 from the left side of the firstlight-shielding layer 111_1 is received by the optical sensing elementPD_1 and a light 300 from the right side of the first light-shieldinglayer 111_1 is received by the optical sensing element PD_1.Accordingly, in a phase detection method used in an image sensor of thepresent disclosure, it is possible to determine whether an image sensoris in-focus based on a difference in the amount of light received by thefirst phase detection sub pixel PPX_a1 and the second phase detectionsub pixel PPX_a2, by using the first and second phase detection subpixels PPX_a1 and PPX_a2 in which light-shielding layers are disposed atdifferent positions. Furthermore, it is also possible to calculate thedirection and distance the lens 1110 (of FIG. 1) needs to be moved inorder to be in-focus. By using the first and second phase detection subpixels PPX_a1 and PPX_a2, it can be determined whether or not the lens1110 is in-focus in a horizontal direction.

The description may be applied to the third and fourth phase detectionsub pixels PPX_a3 and PPX_a4 of FIG. 4B, and it can be determinedwhether or not the lens 1110 is in-focus in a vertical direction byusing the third and fourth phase detection sub pixels PPX_a3 and PPX_a4.

FIGS. 6A to 6C are views for explaining arrangements of a plurality ofshared pixels included in the pixel array of FIG. 3. FIGS. 6A and 6Billustrate pixel arrays 110 a_1 and 110 a_2 including the first andsecond shared phase detection pixels SPPX_a1 and SPPX_a2 of FIG. 4A, andFIG. 6C illustrates a pixel array 110 a_3 including the third and fourthshared phase detection pixels SPPX_a3 and SPPX_a4 of FIG. 4B.

Referring to FIG. 6A, the pixel array 110 a_1 may include a plurality ofshared image sensing pixels SIPX_R, SIPX_G, and SIPX_B, first sharedphase detection pixels SPPX_a1, and second shared phase detection pixelsSPPX_a2. The plurality of shared image sensing pixels SIPX_R, SIPX_G,and SIPX_B may include the plurality of shared image sensing pixelsSIPX_R including a red color filter, the plurality of shared imagesensing pixels SIPX_G including a green color filter, and the pluralityof shared image sensing pixels SIPX_B including a blue color filter.

Each of the first and second shared phase detection pixels SPPX_a1 andSPPX_a2 may be arranged in pairs in the pixel array 110 a_1. Therefore,the number of the first shared phase detection pixels SPPX_a1 and thenumber of the second shared phase detection pixels SPPX_a2 disposed inthe pixel array 110 a_1 may be the same. Each of the first shared phasedetection pixel SPPX_a1 and the second shared phase detection pixelSPPX_a2 as a pair may include a plurality of groups SPPX_P1 to SPPX_P4.

Three shared image sensing pixels may be arranged in a column directionbetween the first shared phase detection pixel SPPX_a1 and the secondshared phase detection pixel SPPX_a2 each constituting the plurality ofgroups SPPX_P1 to SPPX_P4. The pair of the first and second shared phasedetection pixels SPPX_a1 and SPPX_a2 may be arranged in the same columnand connected to the same column output line.

When the first and second shared phase detection pixels SPPX_a1 andSPPX_a2 as a pair are disposed at a distance from each other, the amountof light incident on the first shared phase detection pixel SPPX_a1 andthe amount of light incident on the second shared phase detection pixelSPPX_a2 are different from each other irrespective of the presence orabsence of a light shielding layer. Therefore, it may be inaccurate tocalculate whether or not the lens 1110 (of FIG. 1) is in-focus andaccordingly to calculate a moving direction and a moving distance of thelens 1110.

Meanwhile, when the first and second shared phase detection pixelsSPPX_a1 and SPPX_a2 are adjacent to each other, it may be difficult tocompensate the plurality of shared image sensing pixels SIPX_R, SIPX_G,and SIPX_B disposed around the first and second shared phase detectionpixels SPPX_a1 and SPPX_a2. Since the compensation is performed usingdata of pixels adjacent to a corresponding pixel, a compensationoperation of a shared image sensing pixel adjacent to both the first andsecond shared phase detection pixels SPPX_a1 and SPPX_a2 may becomeinaccurate. Therefore, when three shared image sensing pixels aredisposed between the first and second shared phase detection pixelsSPPX_a1 and SPPX_a2, a focus detection operation and a compensationoperation may be efficiently performed.

A ratio of the number of the first shared phase detection pixels SPPX_a1and the second shared phase detection pixels SPPX_a2 to the number of aplurality of shared pixels arranged in the pixel array 110 a_1 may havea value of 1/32. For example, in the pixel array 110 a_1, four of thefirst shared phase detection pixels SPPX_a1 and four of the second phasedetection pixels SPPX_a2 may be arranged when a plurality of sharedpixels are arranged in 16 in a row direction and in 16 in a columndirection (16>16), and a total of eight phase detection sub pixels maybe arranged. When comparing the first group SPPX_P1 with the third groupSPPX_P3, the first and second shared phase detection pixels SPPX_a1 andSPPX_a2 as a pair may be arranged to be the reverse of that shown inFIG. 6A.

In an example embodiment, the first group SPPX_P1 and the second groupSPPX_P2 may be arranged in the same row and spaced apart from each otherby seven shared image sensing pixels in a row direction. The first groupSPPX_P1 and the third group SPPX_P3 may be arranged apart from eachother by three shared image sensing pixels in a column direction and bythree shared image sensing pixels in a row direction. However, thepresent disclosure is not limited thereto. In another exampleembodiment, the first group SPPX_P1 and the third group SPPX_P3 may bearranged in the same column, and may be arranged apart from each otherby three shared image sensing pixels in a column direction. Thus, in thepixel array 110 a_1 according to an example embodiment of the presentdisclosure, phase detection sub pixels may be arranged to meet the ratioof 1/32 and arrangements of the first shared phase detection pixelsSPPX_a1 and the second shared phase detection pixels SPPX_a2 includingthe phase detection sub pixels may differ from those shown in FIG. 6A.

Referring to FIG. 6B, a ratio of the number of the first shared phasedetection pixels SPPX_a1 and the second shared phase detection pixelsSPPX_a2 to the number of a plurality of shared pixels arranged in thepixel array 110 a_2 may have a value of 1/64. For example, in the pixelarray 110 a_2, two of the first shared phase detection pixels SPPX_a1and two of the second phase detection pixels SPPX_a2 may be arrangedwhen a plurality of shared pixels are arranged in 16 in a row directionand in 16 in a column direction (16×16), and a total of four phasedetection sub pixels may be arranged.

In an example embodiment, the first group SPPX_P1 and the second groupSPPX_P2 may be arranged in the same row and spaced apart from each otherby seven shared image sensing pixels in a row direction. However,arrangements of shared pixels included in the pixel array 110 a_2 arenot limited to those shown in FIG. 6B, and the first and second sharedphase detection pixels SPPX_a1 and SPPX_a2 including phase detection subpixels may be arranged unlike that shown in FIG. 6B such that the phasedetection sub pixels meet the ratio of 1/64.

Referring to FIG. 6C, the pixel array 110 a_3 may include a plurality ofshared image sensing pixels SIPX_R, SIPX_G, and SIPX_B, third sharedphase detection pixels SPPX_a3, and fourth shared phase detection pixelsSPPX_a4. The third and fourth shared phase detection pixels SPPX_a3 andSPPX_a4 may be arranged in pairs in the pixel array 110 a_3, and thusthe number of third shared phase detection pixels SPPX_a3 and the numberof fourth shared phase detection pixels SPPX_a4 that are disposed in thepixel array 110 a_3 may be the same as each other. Each of the thirdshared phase detection pixel SPPX_a3 and the fourth shared phasedetection pixel SPPX_a4 as a pair may include a plurality of groupsSPPX_P1′ to SPPX_P4′.

The third shared phase detection pixels SPPX_a3 and the fourth sharedphase detection pixels SPPX_a4 each constituting the plurality of groupsSPPX_P1′ to SPPX_P4′ may be arranged in the same row, and three sharedimage sensing pixels may be arranged between each of the third sharedphase detection pixels SPPX_a3 and the fourth shared phase detectionpixels SPPX_a4 in a row direction. Therefore, a focus detectionoperation and a compensation operation may be efficiently performed.

A ratio of the number of the third and fourth shared phase detectionpixels SPPX_a3 and SPPX_a4 to the number of a plurality of shared pixelsarranged in the pixel array 110 a_3 may have a value of 1/32. Forexample, in the pixel array 110 a_1, four of the third shared phasedetection pixels SPPX_a3 and four of the fourth shared phase detectionpixels SPPX_a4 may be arranged when a plurality of shared pixels arearranged in 16 in a row direction and in 16 in a column direction(16×16), and a total of eight phase detection sub pixels may bearranged.

In an example embodiment, the first group SPPX_P1′ and the second groupSPPX_P2′ may be arranged in the same column and spaced apart from eachother by seven shared image sensing pixels in a column direction. Thefirst group SPPX_P1′ and the third group SPPX_P3′ may be arranged apartfrom each other by three shared image sensing pixels in a columndirection and by three shared image sensing pixels in a row direction.However, the present disclosure is not limited thereto. In anotherexample embodiment, the first group SPPX_P1′ and the third groupSPPX_P3′ may be arranged in the same row, and may be arranged apart fromeach other by three shared image sensing pixels in a row direction.Thus, in the pixel array 110 a_3 according to an example embodiment ofthe present disclosure, phase detection sub pixels may be arranged tomeet the ratio of 1/32 and arrangements of the third shared phasedetection pixel SPPX_a3 and the fourth shared phase detection pixelSPPX_a4 including the phase detection sub pixels may be different fromthose shown in FIG. 6C.

In another example embodiment, a ratio of the number of the third andfourth shared phase detection pixels SPPX_a3 and SPPX_a4 to the numberof a plurality of shared pixels arranged in the pixel array 110 a_3 mayhave a value of 1/64. For example, when a plurality of shared pixels arearranged in 16 in a row direction and in 16 in a column direction(16×16), two of the third shared phase detection pixels SPPX_a3 and twoof the fourth shared phase detection pixels SPPX_a4 may be arranged inthe pixel array 110 a_3 such that a total of four phase detection subpixels may be arranged.

Referring to FIGS. 6A to 6C, the pixel array 110 (of FIG. 2) may includeall of the first to fourth shared phase detection pixels SPPX_a1 toSPPX_a4. Here, the pixel array 110 (of FIG. 2) may be arranged such thata ratio of the number of phase detection sub pixels to the number of aplurality of shared pixels is 1/32 or 1/64.

An image sensor including the pixel arrays 110 a_1 to 110 a_3 accordingto an example embodiment of the inventive concept includes a pluralityof phase detection pixels at an appropriate ratio, so that the imagesensor may provide a high-resolution image while providing aphase-difference AF function.

FIG. 7 is a detailed view for explaining a connection between the rowdriver 140 of FIG. 2 and the pixel array 110 a_1 of FIG. 6A, and shows aportion B of the pixel array 110 a_1 and lines connected to the portionB.

Referring to FIG. 7, the pixel array B may be connected to the rowdriver 140 (of FIG. 2) via transmission control signal lines TG_AF1 toTG_AF4, TG_E1, TG_O1, TG_E2, and TG_O2, a reset signal line RG, and aselection signal line SEL. A plurality of sub pixels included in oneshared pixel may be connected to the same selection signal line SEL.

Each of row lines Row0 and Row1 may include the transmission controlsignal lines TG_E1, TG_O1, TG_E2, and TG_O2 for providing controlsignals for obtaining image information and the transmission controlsignal lines TG_AF1 to TG_AF4 for providing control signals for phasedifference detection. Thus, each of the row lines Row0 and Row1 mayinclude at least four transmission control signal lines.

Since the first shared phase detection pixel SPPX_a1 needs to output aphase signal different from an image signal, separate transmissioncontrol signal lines TG_E1, TG_O1, TG_E2, and TG_O2 may be connectedthereto. When the first phase detection sub pixel PPX_a1 outputs a phasesignal, a transmission control signal may be transmitted to the firstshared phase detection pixel SPPX_a1 so that the image sensing pixelsIPX_G included in the first shared phase detection pixel SPPX_a1 do notoutput image signals.

The description of FIG. 7 may be applied to the second to fourth sharedphase detection pixels SPPX_a2 to SPPX_a4 (of FIGS. 4A and 4B) inaddition to the first shared phase detection pixel SPPX_a1. However,when the first phase detection sub pixel PPX_a1 outputs a phase signal,a transmission control signal may be transmitted to the second sharedphase detection pixel SPPX_a2 so that the second shared phase detectionpixel SPPX_a2 may also output a phase signal. Furthermore, when thethird phase detection sub pixel PPX_a3 of the third shared phasedetection pixel SPPX_a3 outputs a phase signal, a transmission controlsignal may be transmitted to the fourth shared phase detection pixelSPPX_a4 so that the fourth shared phase detection pixel SPPX_a4 may alsooutput a phase signal.

FIG. 8 is a view for explaining an example embodiment of the sharedphase detection pixel SPPX of FIG. 3.

Referring to FIG. 8, the shared phase detection pixel SPPX of FIG. 3 maybe a first shared phase detection pixel SPPX_b1 or a second shared phasedetection pixel SPPX_b2. The first shared phase detection pixel SPPX_b1may include two phase detection sub pixels PPX_b1 and PPX_b2 and thesecond shared phase detection pixel SPPX_b2 may also include two phasedetection sub pixels PPX_b3 and PPX_b4. Each of the first shared phasedetection pixel SPPX_b1 and the second shared phase detection pixelSPPX_b2 may include the plurality of remaining image sensing pixelsIPX_G except for phase detection sub pixels, and each of the pluralityof image sensing pixels IPX_G may include a micro lens ML_I.

The first phase detection sub pixel PPX_b1 and the second phasedetection sub pixel PPX_b2 may be arranged adjacent to each other in arow direction and the third phase detection sub pixel PPX_b3 and thefourth phase detection sub pixel PPX_b4 may be arranged adjacent to eachother in a column direction. The first phase detection sub pixel PPX_b1and the second phase detection sub pixel PPX_b2 may share a first microlens ML_H and the third phase detection sub pixel PPX_b3 and the fourthphase detection sub pixel PPX_b4 may share a second micro lens ML_V.

The first phase detection sub pixel PPX_b1 and the second phasedetection sub pixel PPX_b2 may output different phase signals dependingon a shape and a refractive index of the first micro lens ML_H. Based onthe respective phase signals output from the first phase detection subpixel PPX_b1 and the second phase detection sub pixel PPX_b2, it can bedetermined whether the lens 1110 (of FIG. 1) is in-focus in a horizontaldirection.

The third phase detection sub pixel PPX_b3 and the fourth phasedetection sub pixel PPX_b4 may output different phase signals dependingon a shape and a refractive index of the second micro lens ML_V. Basedon the respective phase signals output from the third phase detectionsub pixel PPX_b3 and the fourth phase detection sub pixel PPX_b4, it canbe determined whether the lens 1110 (of FIG. 1) is in-focus in avertical direction.

In an example embodiment, the plurality of image sensing pixels IPX_Gmay include a green color filter, and each of the first to fourth phasedetection sub pixels PPX_b1 to PPX_b4 may also include a green colorfilter. However, the present disclosure is not limited thereto. Inanother example embodiment, each of the first to fourth phase detectionsub pixels PPX_b1 to PPX_b4 may include a white color filter.

A pixel array including the first shared phase detection pixel SPPX_b1or the second shared phase detection pixel SPPX_b2 may also be connectedto the row driver 140 (FIG. 2) in a manner similar to that shown in FIG.7.

FIG. 9 is a view for explaining arrangements of a plurality of sharedpixels included in the pixel array of FIG. 3. FIG. 9 shows a pixel array110 a_4 including the first shared phase detection pixel SPPX_b1 of FIG.8. In FIG. 9, like reference numerals in FIG. 6A denote like elements,and a duplicate description will be omitted for simplicity.

Referring to FIG. 9, a ratio of the number of a plurality of phasedetection sub pixels to the number of a plurality of shared pixelsarranged in the pixel array 110 a_4 may have a value of 1/32. Forexample, in the pixel array 110 a_4, four of the first shared phasedetection pixels SPPX_b1 may be arranged when a plurality of sharedpixels are arranged in 16 in a row direction and in 16 in a columndirection (16×16), and a total of eight phase detection sub pixels maybe arranged. However, the present disclosure is not limited thereto, anda ratio of the number of a plurality of phase detection sub pixels tothe number of a plurality of shared pixels arranged in the pixel array110 a_4 may have a value of 1/64. For example, in the pixel array 110a_4, two of the first shared phase detection pixels SPPX_b1 (not shown)may be arranged when a plurality of shared pixels are arranged in 16 ina row direction and in 16 in a column direction (16×16), and a total offour phase detection sub pixels may be arranged.

In the pixel array 110 a_4 according to an example embodiment of thepresent disclosure, phase detection sub pixels may be arranged to meetthe ratio of 1/32 or 1/64, and thus an arrangement of the first sharedphase detection pixels SPPX_b1 including the phase detection sub pixelsmay be different from that shown in FIG. 9.

Although only the first shared phase detection pixels SPPX_b1 are shownin FIG. 9, a pixel array of another example embodiment may include aplurality of second shared phase detection pixels SPPX_b2, andarrangements of the second shared phase detection pixels SPPX_b2 may bethe same as that of the first shared phase detection pixels SPPX_b1 ofFIG. 9. Alternatively, a pixel array of another example embodimentincludes all of the plurality of first shared phase detection pixelsSPPX_b1 and the plurality of second shared phase detection pixelsSPPX_b2, wherein the plurality of first shared phase detection pixelsSPPX_b1 and the plurality of second shared phase detection pixelsSPPX_b2 may be arranged in the pixel array such that phase detection subpixels may meet the ratio of 1/32 or 1/64.

FIG. 10 is a view for explaining an example embodiment of the sharedphase detection pixel SPPX of FIG. 3.

Referring to FIG. 10, the shared phase detection pixel SPPX of FIG. 3may be a shared phase detection pixel SPPX_c. The shared phase detectionpixel SPPX_c may include four phase detection sub pixels PPX_c1 toPPX_c4. The four phase detection sub pixels PPX_c1 to PPX_c4 included inone shared phase detection pixel SPPX_c may share one micro lens ML_Q.Four image sensing sub pixels included in each of the plurality ofshared image sensing pixels SIPX0 to SIPX14 (of FIG. 3) may also shareone micro lens. However, the present disclosure is not limited theretoand each of a plurality of image sensing sub pixels may include onemicro lens.

Since the first to fourth phase detection sub pixels PPX_c1 to PPX_c4are located in different rows or columns, the first to fourth phasedetection sub pixels PPX_c1 to PPX_c4 may output different phase signalsdepending on a shape and a refractive index of the micro lens ML_Q.Based on the different phase signals, it can be determined whether thelens 1110 (of FIG. 1) is in-focus in a horizontal direction or in avertical direction.

In an example embodiment, each of the first to fourth phase detectionsub pixels PPX_c1 to PPX_c4 may include a green color filter. However,the present disclosure is not limited thereto. In another exampleembodiment, each of the first to fourth phase detection sub pixelsPPX_c1 to PPX_c4 may include a white color filter.

FIG. 11 is a view for explaining arrangements of a plurality of sharedpixels included in the pixel array of FIG. 3. FIG. 11 shows a pixelarray 110 a_5 including the shared phase detection pixel SPPX_c of FIG.10. In FIG. 11, like reference numerals in FIG. 6A denote like elements,and a duplicate description will be omitted for simplicity.

Referring to FIG. 11, a ratio of the number of a plurality of phasedetection sub pixels to the number of a plurality of shared pixelsarranged in the pixel array 110 a_5 may have a value of 1/32. Forexample, in the pixel array 110 a_5, two shared phase detection pixelsSPPX_c may be arranged when a plurality of shared pixels are arranged in16 in a row direction and in 16 in a column direction (16×16), and atotal of eight phase detection sub pixels may be arranged. However, thepresent disclosure is not limited thereto, and a ratio of the number ofa plurality of phase detection sub pixels to the number of a pluralityof shared pixels arranged in the pixel array 110 a_5 may have a value of1/64. Therefore, an arrangement of the shared phase detection pixelsSPPX_c including the phase detection sub pixels may be different fromthat of FIG. 11.

FIG. 12 is a detailed view for explaining a connection between the rowdriver 140 of FIG. 2 and the pixel array 110 a_5 of FIG. 10, and shows aportion C of the pixel array 110 a_5 and lines connected to the portionC.

Referring to FIGS. 11 and 12, the pixel array 110 a_5 may include along-time exposure shared pixel L and a short-time exposure shared pixelS. The long-time exposure shared pixel L is a shared pixel for beingsuccessively exposed within a constant exposure period to generate apixel signal, and the short-time exposure shared pixel S is a sharedpixel for being intermittently exposed within a constant exposure periodto generate a pixel signal. The long-time exposure shared pixel L mayinclude a plurality of photodiodes for long-time exposure and theshort-time exposure shared pixel S may include a plurality ofphotodiodes for short-time exposure. However, FIG. 12 is for explainingan example embodiment of the present disclosure, and the presentdisclosure is not limited to the arrangement of FIG. 12.

The pixel array C may be connected to the row driver 140 (of FIG. 2) viatransmission control signal lines TG_LE1, TG_LO1, TG_SE1, TG_SO1,TG_LE2, TG_LO2, TG_SE2, and TG_SO2, the reset signal line RG, and theselection signal line SEL. Each of the row lines Row0 and Row1 mayinclude four transmission control signal lines, and may further includethe transmission control signal lines TG_LE1, TG_LO1, TG_LE2, and TG_LO2for providing control signals for long-time exposure, and thetransmission control signal lines TG_SE1, TG_SO1, TG_SE2, and TG_SO2 forproviding control signals for short-time exposure.

A first shared image sensing pixel SIPX_R_L may include four pixelsincluding optical sensing elements for long-time exposure as thelong-time exposure shared pixel L, and each of a second shared imagesensing pixel SIPX_R_S and a third shared image sensing pixel SIPX_G mayinclude four pixels including optical sensing elements for short-timeexposure. The first shared image sensing pixel SIPX_R_L may be connectedto the transmission control signal lines TG_LE1, TG_LO1, TG_LE2, andTG_LO2 that provide control signals for long-time exposure, and each ofthe second shared image sensing pixel SIPX_R_S and the third sharedimage sensing pixel SIPX_G may be connected to the transmission controlsignal lines TG_SE1, TG_SO1, TG_SE2, and TG_SO2 that provide controlsignals for short-time exposure.

Sub pixels included in the shared phase detection pixel SPPX_c are allphase detection sub pixels connected to transmission control signallines that are connected to shared image sensing pixels, and thusseparate transmission control signal lines for Sub pixels included inthe shared phase detection pixel SPPX_c may not be connected to theshared phase detection pixel SPPX_c. FIG. 12 shows that the shared phasedetection pixel SPPX_c is connected to the transmission control signallines TG_LE1, TG_LO1, TG_LE2, and TG_LO2 that provide control signalsfor long-time exposure, but the present disclosure is not limitedthereto. The shared phase detection pixel SPPX_c may also be connectedto the transmission control signal lines TG_SE1, TG_SO1, TG_SE2, andTG_SO2 that provide control signals for short-time exposure.

An image sensor including the pixel array 110 a_5 according to anexample embodiment of the present disclosure may be implemented so as torealize a wide dynamic range effect by using a signal processingtechnique, after capturing images by periodically changing an exposureperiod in one frame. Therefore, the image sensor including the pixelarray 110 a_5 may realize a wide dynamic range effect and may provide aphase difference AF function.

FIG. 13 is a view of an example embodiment of the pixel array 110 ofFIG. 2. A pixel array 110 b of FIG. 13 shows a portion of the pixelarray 110 of FIG. 2. FIG. 14 is a view for explaining an exampleembodiment of shared phase detection pixels SPPX_d1 and SPPX_d2 of FIG.13.

Referring to FIGS. 13 and 14, the pixel array 110 b may include aplurality of shared pixels SPX′ and the plurality of shared pixels SPX′may include a plurality of shared image sensing pixels SIPX0′ toSIPX13′, a first shared phase detection pixel SPPX_d1, and a secondshared phase detection pixel SPPX_d2. The plurality of shared imagesensing pixels SIPX0′ to SIPX13′ may include the plurality of imagesensing pixels IPX (of FIG. 2), and each of the first shared phasedetection pixel SPPX_d1 and the second shared phase detection pixelSPPX_d2 may include one of phase detection sub pixels PPX_d1 and PPX_d2.Each of the first shared phase detection pixel SPPX_d1 and the secondshared phase detection pixel SPPX_d2 may include a plurality ofremaining image sensing pixels IPX_G and IPX_R except for phasedetection sub pixels.

The first shared phase detection pixel SPPX_d1 and the second sharedphase detection pixel SPPX_d2 may be arranged adjacent to each other ina row direction and the first phase detection sub pixel PPX_d1 and thesecond phase detection sub pixel PPX_d2 may be arranged adjacent to eachother in a row direction. However, the present disclosure is not limitedthereto, and the first shared phase detection pixel SPPX_d1 and thesecond shared phase detection pixel SPPX_d2 may be arranged adjacent toeach other in a column direction, and the first phase detection subpixel PPX_d1 and the second phase detection sub pixel PPX_d2 may bearranged adjacent to each other in a column direction.

The first phase detection sub pixel PPX_d1 and the second phasedetection sub pixel PPX_d2 may be arranged in pairs so that the samenumber of first phase detection sub pixels PPX_d1 and second phasedetection sub pixels PPX_d2 may be arranged in the pixel array 110 b.

The first phase detection sub pixel PPX_d1 and the second phasedetection sub pixel PPX_d2 may share one micro lens ML_H. The firstphase detection sub pixel PPX_d1 and the second phase detection subpixel PPX_b2 may output different phase signals depending on a shape anda refractive index of the micro lens ML_H. When the first phasedetection sub pixel PPX_d1 and the second phase detection sub pixelPPX_d2 are arranged adjacent to each other in a row direction, it can bedetermined whether the lens 1110 (of FIG. 1) is in-focus in a horizontaldirection, and when the first phase detection sub pixel PPX_d1 and thesecond phase detection sub pixel PPX_d2 are arranged adjacent to eachother in a column direction, it can be determined whether the lens 1110(of FIG. 1) is in-focus in a vertical direction.

Each of the plurality of shared image sensing pixels SIPX0′ to SIPX13′may include a color filter to sense various colors. In an exampleembodiment, the color filter includes filters that sense red, green, andblue, and each of the shared image sensing pixels SIPX0′ to SIPX13′ mayinclude pixels in which the same color filter is disposed.

In an example embodiment, one of the first and second shared phasedetection pixels SPPX_d1 and SPPX_d2 may include a green color filter.For example, the first shared phase detection pixel SPPX_d1 may includea green color filter and the second shared phase detection pixel SPPX_d2may include a red color filter. However, the present disclosure is notlimited thereto, and each of the first and second phase detection subpixels PPX_d1 and PPX_d2 included in the first and second shared phasedetection pixels SPPX_d1 and SPPX_d2 may include a white color filter.

FIG. 13 respectively shows one of the first and second shared phasedetection pixels SPPX_d1 and SPPX_d2, but in the pixel array 110 b, aratio of the number of the first and second phase detection sub pixelsPPX_d1 and PPX_d2 to the number of a plurality of shared pixels may havea value of 1/32 or 1/64. For example, in the pixel array 110 b, four ofthe first shared phase detection pixels SPPX_d1 and four of the secondphase detection pixels SPPX_d2 or two of the first shared phasedetection pixels SPPX_d1 and two of the second phase detection pixelsSPPX_d2 may be arranged when the plurality of shared pixels SPX′ arearranged in 16 in a row direction and in 16 in a column direction(16×16).

FIGS. 15A to 15C are views for explaining arrangements of a plurality ofpixels included in the pixel array 110 of FIG. 2. Compared to the pixelarrays 110 a and 110 b of FIGS. 3 and 13, the plurality of pixels inFIGS. 15A to 15C do not constitute one shared pixel, and pixels arrangedin the same row may be connected to the same selection signal line.Thus, pixels included in the same row may be simultaneously activated bythe selection signal SELSs (of FIG. 2) output by the row driver 140 (ofFIG. 2).

Referring to FIG. 15A, a pixel array 110 c_1 may include a plurality ofimage sensing pixels IPX_R, IPX_G, and IPX_B, a first phase detectionpixel PPX_a1, and a second phase detection pixel PPX_a2. The pluralityof image sensing pixels IPX_R, IPX_G, and IPX_B may include a pluralityof shared image sensing pixels IPX_R including a red color filter, aplurality of shared image sensing pixels IPX_G including a green colorfilter, and a plurality of shared image sensing pixels IPX_B including ablue color filter.

The first phase detection pixel PPX_a1 and the second phase detectionpixel PPX_a2 may be pixels for phase difference detection AF, and theplurality of image sensing pixels IPX_R, IPX_G, and IPX_B may be generalpixels capable of obtaining only image information. Configurations ofthe first phase detection pixel PPX_a1 and the second phase detectionpixel PPX_a2 of FIG. 15A may be the same as those of the first phasedetection sub pixel PPX_a1 and the second phase detection sub pixelPPX_a2 of FIG. 4A.

Since the first phase detection pixel PPX_a1 and the second phasedetection pixel PPX_a2 are arranged in the pixel array 110 c_1 as a pairso that the same number of first phase detection pixels PPX_a1 andsecond phase detection pixels PPX_a2 may be arranged in the pixel array110 c_1. The first phase detection pixel PPX_a1 and the second phasedetection pixel PPX_a2 as a pair may each constitute a plurality ofgroups PPX_Pa1 to PPX_Pa4.

The first phase detection pixels PPX_a1 and the second phase detectionpixels PPX_a2 each constituting the plurality of groups PPX_Pa1 toPPX_Pa4 may be arranged in the same column, and three image sensingpixels may be arranged between each of the first phase detection pixelsPPX_a1 and the second phase detection pixels PPX_a2 in a columndirection. Therefore, a focus detection operation and a compensationoperation may be efficiently performed.

A ratio of the number of the first phase detection pixel PPX_a1 and thesecond phase detection pixel PPX_a2 to the number of a plurality ofpixels arranged in the pixel array 110 c_1 may have a value of 1/32. Forexample, in the pixel array 110 c_1, four of the first phase detectionpixels PPX_a1 and four of the second phase detection pixels PPX_a2 maybe arranged when a plurality of pixels are arranged in 16 in a rowdirection and in 16 in a column direction (16×16). The first phasedetection pixel PPX_a1 and the second phase detection pixel PPX_a2 as apair may be arranged to be the reverse of that shown in FIG. 15A.

In an example embodiment, the first group PPX_Pa1 and the second groupPPX_Pa2 may be arranged in the same row and spaced apart from each otherby seven image sensing pixels in a row direction. The first groupPPX_Pa1 and the third group PPX_Pa3 may be arranged apart from eachother by three image sensing pixels in a column direction and by threeimage sensing pixels in a row direction. However, the present disclosureis not limited thereto. In another example embodiment, the first groupPPX_Pa1 and the second group PPX_Pa2 may be arranged in different rows.Furthermore, the first group PPX_Pa1 and the third group PPX_Pa3 may bearranged in the same column and spaced apart from each other by threeimage sensing pixels in a column direction. Therefore, arrangements ofthe first phase detection pixels PPX_a1 and the second phase detectionpixels PPX_a2 may be different from those of FIG. 15A.

Referring to FIG. 15B, a phase detection pixel PPX_aP may include thefirst phase detection pixel PPX_a1 and the second phase detection pixelPPX_a2. A ratio of the number of the first phase detection pixels PPX_a1and the second phase detection pixels PPX_a2 to the number of aplurality of pixels arranged in a pixel array 110 c_2 may have a valueof 1/16. For example, in the pixel array 110 c_2, eight of the firstphase detection pixels PPX_a1 and eight of the second phase detectionpixels PPX_a2 may be arranged when a plurality of pixels are arranged in16 in a row direction and in 16 in a column direction (16×16).

However, arrangements of pixels included in the pixel array 110 c_2 arenot limited to those shown in FIG. 15B, and the first and second phasedetection pixels PPX_a1 and PPX_a2 including phase detection pixels maybe arranged unlike those shown in FIG. 15B such that the phase detectionpixels meet the ratio of 1/16.

Referring to FIG. 15C, a pixel array 110 c_3 may include the pluralityof image sensing pixels IPX_R, IPX_G, and IPX_B, the third phasedetection pixel PPX_a3, and the fourth phase detection pixel PPX_a4.Configurations of the third phase detection pixel PPX_a3 and the fourthphase detection pixel PPX_a4 of FIG. 15A may be the same as those of thefirst phase detection sub pixel PPX_a3 and the second phase detectionsub pixel PPX_a4 of FIG. 4B.

Since the third phase detection pixel PPX_a3 and the fourth phasedetection pixel PPX_a4 are arranged in the pixel array 110 c_3 as apair, the same number of third phase detection pixels PPX_a3 and thefourth phase detection pixels PPX_a4 may be arranged in the pixel array110 c_3. Each of the third phase detection pixel PPX_a3 and the fourthphase detection pixel PPX_a4 as a pair may include a plurality of groupsPPX_Pa1′ to PPX_Pa4′.

The third phase detection pixels PPX_a3 and the fourth phase detectionpixels PPX_a4 each constituting the plurality of groups PPX_Pa1′ toPPX_Pa4′ may be arranged in the same row, and three image sensing pixelsmay be arranged between each of the third phase detection pixels PPX_a3and the fourth phase detection pixels PPX_a4 in a row direction.Therefore, a focus detection operation and a compensation operation maybe efficiently performed.

A ratio of the number of the third phase detection pixel PPX_a3 and thefourth phase detection pixel PPX_a4 to the number of a plurality ofpixels arranged in the pixel array 110 c_3 may have a value of 1/32. Forexample, four of the third phase detection pixels PPX_a3 and four of thefourth phase detection pixels PPX_a4 may be arranged in the pixel array110 c_3 when a plurality of pixels are arranged in 16 in a row directionand in 16 in a column direction (16×16), and a total of eight phasedetection pixels may be arranged in the pixel array 110 c_3.

In an example embodiment, the first group PPX_Pa1′ and the second groupPPX_Pa2′ may be arranged in the same column and spaced apart from eachother by seven image sensing pixels in a column direction. The firstgroup PPX_Pa1′ and the third group PPX_Pa3′ may be arranged apart fromeach other by three image sensing pixels in a column direction and bythree image sensing pixels in a row direction. However, the presentdisclosure is not limited thereto. In another example embodiment, thefirst group PPX_Pa1′ and the third group PPX_Pa3′ may be arranged in thesame row, and may be arranged apart from each other by three imagesensing pixels in a row direction only. Therefore, arrangements of thethird phase detection pixels PPX_a3 and the fourth phase detectionpixels PPX_a4 in the pixel array 110 c_3 may be different from those ofFIG. 15C.

In another example embodiment, a ratio of the number of the third phasedetection pixels PPX_a3 and the fourth phase detection pixels PPX_a4 tothe number of a plurality of pixels arranged in the pixel array 110 c_3may have a value of 1/16. For example, when a plurality of pixels arearranged in 16 in a row direction and in 16 in a column direction(16×16), eight of the third phase detection pixels PPX_a3 and eight ofthe fourth phase detection pixels PPX_a4 may be arranged in the pixelarray 110 c_3 such that a total of 16 phase detection pixels may bearranged.

Referring to FIGS. 15A to 15C, the pixel array 110 (of FIG. 2) mayinclude all of the first to fourth phase detection pixels PPX_a1 toPPX_a4. A ratio of the number of the first to fourth phase detectionpixels PPX_a1 to PPX_a4 to the number of a plurality of pixels arrangedin the pixel array 110 may have a value of 1/16 or 1/32.

An image sensor including the pixel arrays 110 c_1 to 110 c_3 accordingto an example embodiment of the inventive concept includes a pluralityof phase detection pixels at an appropriate ratio, so that the imagesensor may provide a high-resolution image while providing aphase-difference AF function.

FIGS. 16A and 16B are views for explaining arrangements of a pluralityof pixels included in the pixel array 110 of FIG. 2. Compared to thepixel arrays 110 a and 110 b of FIGS. 3 and 13, the plurality of pixelsin FIGS. 16A and 16B do not constitute one shared pixel, and pixelsarranged in the same row may be connected to the same selection signalline.

Referring to FIG. 16A, a pixel array 110 d_1 may include the pluralityof image sensing pixels IPX_R, IPX_G, and IPX_B, a first phase detectionpixel PPX_b1, and a second phase detection pixel PPX_b2. Configurationsof the first phase detection pixel PPX_b1 and the second phase detectionpixel PPX_b2 of FIG. 16A may be the same as those of the first phasedetection sub pixel PPX_b1 and the second phase detection sub pixelPPX_b2 of FIG. 8.

The first and second phase detection pixels PPX_b1 and PPX_b2 may bearranged in a pixel array 110 d_1 adjacent to each other in a rowdirection and may be arranged in pairs. Therefore, the number of firstphase detection pixels PPX_b1 and the number of second phase detectionpixels PPX_b2 arranged in the pixel array 110 d_1 may be equal to eachother. Each of the first phase detection pixel PPX_b1 and the secondphase detection pixel PPX_b2 as a pair may include a plurality of groupsPPX_Pb1 to PPX_Pb4.

A ratio of the number of the first phase detection pixel PPX_b1 and thesecond phase detection pixel PPX_b2 to the number of a plurality ofpixels arranged in the pixel array 110 d_1 may have a value of 1/32. Forexample, four of the groups PPX_Pb1 to PPX_Pb4 may be arranged in thepixel array 110 d_1 when a plurality of pixels are arranged in 16 in arow direction and in 16 in a column direction (16×16). However, thepresent disclosure is not limited thereto, and a ratio of the number ofthe first phase detection pixels PPX_b1 and the second phase detectionpixels PPX_b2 to the number of a plurality of pixels arranged in thepixel array 110 d_1 may have a value of 1/16.

In an example embodiment, the first group PPX_P1 and the second groupPPX_P2 may be arranged in the same row and the first group PPX_P1 andthe third group PPX_Pb3 may be arranged in the same column.

In the pixel array 110 d_1 according to an example embodiment of thepresent disclosure, phase detection pixels may be arranged to meet theratio of 1/32 or 1/16, and thus arrangements of the plurality of groupsPPX_Pb1 to PPX_Pb4 may be different from those shown in FIG. 16A.

Referring to FIG. 16B, a pixel array 110 d_2 may include the pluralityof image sensing pixels IPX_R, IPX_G, and IPX_B, a third phase detectionpixel PPX_b3, and a fourth phase detection pixel PPX_b4. Configurationsof the third phase detection pixel PPX_b3 and the fourth phase detectionpixel PPX_b4 of FIG. 16b may be the same as those of the third phasedetection sub pixel PPX_b3 and the fourth phase detection sub pixelPPX_b4 of FIG. 8.

The third phase detection pixel PPX_b3 and the fourth phase detectionpixel PPX_b4 may be arranged in the pixel array 110 d_2 adjacent to eachother in a column direction and may be arranged in pairs. Therefore, thenumber of third phase detection pixels PPX_b3 and the number of fourthphase detection pixels PPX_b4 arranged in the pixel array 110 d_2 may beequal to each other. Each of the third phase detection pixel PPX_b3 andthe fourth phase detection pixel PPX_a4 as a pair may include aplurality of groups PPX_Pb1′ to PPX_Pb4′.

A ratio of the number of the third phase detection pixels PPX_b3 and thefourth phase detection pixels PPX_b4 to the number of a plurality ofpixels arranged in the pixel array 110 d_2 may have a value of 1/32. Forexample, four of the groups PPX_Pb1′ to PPX_Pb4′ may be arranged in thepixel array 110 d_2 when a plurality of pixels are arranged in 16 in arow direction and in 16 in a column direction (16×16). However, thepresent disclosure is not limited thereto, and a ratio of the number ofthe third phase detection pixels PPX_b3 and the fourth phase detectionpixels PPX_b4 to the number of a plurality of pixels arranged in thepixel array 110 d_2 may have a value of 1/16.

In an example embodiment, the first group PPX_Pb1′ and the second groupPPX_Pb2′ may be arranged in the same row and the first group PPX_Pb1′and the third group PPX_Pb3′ may be arranged in the same column. In thepixel array 110 d_2 according to an example embodiment of the presentdisclosure, phase detection pixels may be arranged to meet the ratio of1/32 or 1/16, and thus arrangements of the plurality of groups PPX_Pb1′to PPX_Pb4′ may be different from those shown in FIG. 16B.

Referring to FIGS. 16A and 16B, the pixel array 110 (of FIG. 2) mayinclude all of the first to fourth phase detection pixels PPX_b1 toPPX_b4. A ratio of the number of the first to fourth phase detectionpixels PPX_b1 to PPX_b4 to the number of a plurality of pixels arrangedin the pixel array 110 may have a value of 1/16 or 1/32.

An image sensor including the pixel arrays 110 d_1 and 110 d_2 accordingto an example embodiment of the inventive concept includes a pluralityof phase detection pixels at an appropriate ratio, so that the imagesensor may provide a high-resolution image while providing aphase-difference AF function.

While the inventive concept has been particularly shown and describedwith reference to example embodiments thereof, it will be understoodthat various changes in form and details may be made therein withoutdeparting from the spirit and scope of the following claims.

What is claimed is:
 1. An image sensor including a pixel array whichprovides a plurality of pixels arranged in rows and columns, wherein theplurality of pixels comprises: a plurality of image sensing pixels eachincluding a plurality of image sensing sub pixels that include the samecolor filter; and a plurality of phase detection pixels each includingat least one phase detection sub pixel configured to generate a phasesignal for calculating a phase difference between images, wherein theplurality of image sensing sub pixels included in the same image sensingpixel are connected to one selection signal line and receive the sameselection signal, and wherein each phase detection pixel includes animage sensing sub pixel, and the at least one phase detection sub pixeland the image sensing sub pixel included in the same phase detectionpixel are connected to the same selection signal line and share the samecolor filter.
 2. The image sensor of claim 1, wherein a ratio of thenumber of phase detection sub pixels arranged in the pixel array to thenumber of the plurality of pixels arranged in the pixel array is 1/32 or1/64.
 3. The image sensor of claim 1, wherein each of the plurality ofphase detection pixels includes one phase detection sub pixel includingan optical sensing element and a light-shielding layer, wherein thelight-shielding layer is configured to shield some of light incident onthe optical sensing element.
 4. The image sensor of claim 3, wherein theplurality of phase detection pixels includes a first phase detectionpixel and a second phase detection pixel, wherein the first phasedetection pixel and the second phase detection pixel are arranged in thesame row or column, and three image sensing pixels are arranged betweenthe first phase detection pixel and the second phase detection pixel. 5.The image sensor of claim 1, wherein each of the plurality of phasedetection pixels includes two phase detection sub pixels arrangedadjacent to each other in a row direction, wherein the two phasedetection sub pixels included in the same phase detection pixel includethe same color filter and one micro lens formed on the same colorfilter.
 6. The image sensor of claim 1, wherein each of the plurality ofphase detection pixels includes two phase detection sub pixels arrangedadjacent to each other in a column direction, wherein the two phasedetection sub pixels included in the same phase detection pixel includethe same color filter and one micro lens formed on the same colorfilter.
 7. The image sensor of claim 1, wherein the plurality of phasedetection pixels further include a green color filter or a blue colorfilter.
 8. The image sensor of claim 1, wherein the plurality of phasedetection pixels further include a white color filter.
 9. An imagesensor including a pixel array providing a plurality of pixels arrangedin a first direction and a second direction, wherein the plurality ofpixels comprise: a plurality of image sensing pixels each configured togenerate an image signal; and a first phase detection pixel and a secondphase detection pixel configured to generate different phase signals forcalculating phase differences between images, wherein a ratio of thenumber of the first phase detection pixels and the number of the secondphase detection pixels to the number of the plurality of pixels arrangedin the pixel array has a value of 1/16 or 1/32, wherein each of thefirst phase detection pixel and the second phase detection pixelincludes an optical sensing element and a light-shielding layer formedon the optical sensing element, and wherein the first phase detectionpixel and the second phase detection pixel are arranged in the firstdirection and three image sensing pixels are arranged between the firstphase detection pixel and the second phase detection pixel in the firstdirection.
 10. The image sensor of claim 9, wherein the first directionis a column direction.
 11. The image sensor of claim 9, wherein thefirst direction is a row direction.
 12. The image sensor of claim 9,wherein the first phase detection pixel and the second phase detectionpixel include one of a green color filter, a blue color filter, and awhite color filter.
 13. An image sensor comprising: a pixel arrayincluding a plurality of phase detection pixels and a plurality of imagesensing pixels; and a row driver configured to generate signals forcontrolling the pixel array, wherein each of the plurality of phasedetection pixels includes at least one phase detection sub pixel,wherein each of the plurality of image sensing pixels includes aplurality of image sensing sub pixels connected to the row driverthrough one selection signal line and receive the same selection signal,wherein each of the plurality of phase detection pixels includes fourphase detection sub pixels sharing one micro lens, wherein the pluralityof image sensing pixels includes a first image sensing pixel and asecond image sensing pixel, and wherein the first image sensing pixel,the second image sensing pixel, and a portion of the plurality of phasedetection pixels are arranged in the same row.
 14. The image sensor ofclaim 13, wherein the row driver is configured to transmit a firsttransmission control signal to a first image sensing pixel such that thefirst optical sensing element is exposed for a first time period, and totransmit a second transmission control signal to a second image sensingpixel such that the second optical sensing element is exposed for asecond time period different from the first time period.